Dual durometer insulating boot for electrosurgical forceps

ABSTRACT

An electrosurgical forceps includes a shaft having a pair of jaw members at a distal end and movable about a pivot from a first position and disposed in spaced relation relative to one another to a second position wherein the jaw members are closer to one another for grasping tissue, a movable handle that actuates a drive assembly to move the jaw members relative to one another. At least one jaw member conducts electrical energy to tissue held therebetween. A flexible insulating boot is disposed on an exterior surface of at least one jaw member and about the pivot and includes a first longitudinal portion made from a high durometer material and a second longitudinal portion made from a low durometer material. The high durometer material may operably retain the flexible insulating boot atop the proximal ends of the jaw members.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of, and claims the benefit of andpriority to, U.S. patent application Ser. No. 12/212,333, filed on Sep.17, 2008, “DUAL DUROMETER INSULATING BOOT FOR ELECTROSURGICAL FORCEPS”,by Guerra et al., published as U.S. Patent Application Publication No.US 2009/0088738 A1 on Apr. 2, 2009, now U.S. Pat. No. 8,241,283, andU.S. Provisional Patent Application No. 60/995,865 by Guerra et al.,filed on Sep. 28, 2007, the entire contents of each of which is herebyincorporated by reference herein.

BACKGROUND

1. Technical Field

The present disclosure relates to an insulated electrosurgical forcepsand more particularly, the present disclosure relates to an insulatingboot for use with either an endoscopic or open bipolar and/or monopolarelectrosurgical forceps for sealing, cutting, and/or coagulating tissue.

2. Background of Related Art

Electrosurgical forceps utilize both mechanical clamping action andelectrical energy to effect hemostasis by heating the tissue and bloodvessels to coagulate, cauterize and/or seal tissue. As an alternative toopen forceps for use with open surgical procedures, many modern surgeonsuse endoscopes and endoscopic instruments for remotely accessing organsthrough smaller, puncture-like incisions. As a direct result thereof,patients tend to benefit from less scarring and reduced healing time.

Endoscopic instruments are inserted into the patient through a cannula,or port, which has been made with a trocar. Typical sizes for cannulasrange from three millimeters to twelve millimeters. Smaller cannulas areusually preferred, which, as can be appreciated, ultimately presents adesign challenge to instrument manufacturers who must find ways to makeendoscopic instruments that fit through the smaller cannulas.

Many endoscopic surgical procedures require cutting or ligating bloodvessels or vascular tissue. Due to the inherent spatial considerationsof the surgical cavity, surgeons often have difficulty suturing vesselsor performing other traditional methods of controlling bleeding, e.g.,clamping and/or tying-off transected blood vessels. By utilizing anendoscopic electrosurgical forceps, a surgeon can either cauterize,coagulate/desiccate and/or simply reduce or slow bleeding simply bycontrolling the intensity, frequency and duration of the electrosurgicalenergy applied through the jaw members to the tissue. Most small bloodvessels, i.e., in the range below two millimeters in diameter, can oftenbe closed using standard electrosurgical instruments and techniques.However, if a larger vessel is ligated, it may be necessary for thesurgeon to convert the endoscopic procedure into an open-surgicalprocedure and thereby abandon the benefits of endoscopic surgery.Alternatively, the surgeon can seal the larger vessel or tissue.

It is thought that the process of coagulating vessels is fundamentallydifferent than electrosurgical vessel sealing. For the purposes herein,“coagulation” is defined as a process of desiccating tissue wherein thetissue cells are ruptured and dried. “Vessel sealing” or “tissuesealing” is defined as the process of liquefying the collagen in thetissue so that it reforms into a fused mass. Coagulation of smallvessels is sufficient to permanently close them, while larger vesselsneed to be sealed to assure permanent closure.

A general issue with existing electrosurgical forceps is that the jawmembers rotate about a common pivot at the distal end of a metal orotherwise conductive shaft such that there is potential for both thejaws, a portion of the shaft, and the related mechanism components toconduct electrosurgical energy (either monopolar or as part of a bipolarpath) to the patient tissue. Existing electrosurgical instruments withjaws either cover the pivot elements with an inflexible shrink-tube ordo not cover the pivot elements and connection areas and leave theseportions exposed.

SUMMARY

An electrosurgical forceps includes a shaft having a pair of jaw membersat a distal end thereof the jaw members movable about a pivot from afirst position wherein the jaw members are disposed in spaced relationrelative to one another to a second position wherein the jaw members arecloser to one another for grasping tissue, a movable handle thatactuates a drive assembly to move the jaw members relative to oneanother. At least one of the jaw members includes at least onemechanical interface and at least one jaw member is adapted to connectto a source of electrical energy such that the at least one jaw memberis capable of conducting energy to tissue held therebetween. A flexibleinsulating boot is disposed on at least a portion of an exterior surfaceof at least one jaw member and about the pivot, the flexible bootincluding a first longitudinal portion made from a high durometermaterial and a second longitudinal portion made from a low durometermaterial. The high durometer material may be configured to operablyretain the flexible insulating boot atop both the proximal ends of thejaw members.

The high durometer material may be disposed at a distal end of theflexible insulating boot, and may include an aperture defined thereinwhich is configured to operably receive a proximal end of each jawmember therethrough.

Each jaw member may include a proximal flange associated therewith andthe shaft may define an outer periphery, and wherein the low durometermaterial may stretch to allow the proximal flange of each jaw member torotate beyond the outer periphery of the shaft.

The high durometer portion may include proximally-extending fingerswhich define upper and lower slots therein that are dimensioned toreceive corresponding upper and lower low durometer portions duringco-extrusion of the flexible insulating boot.

Each jaw member may include a proximal flange associated therewith andthe shaft may define an outer periphery, and wherein the low durometermaterial may be oriented to stretch and allow the proximal flange ofeach jaw member to rotate beyond the outer periphery of the shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the subject instrument are described herein withreference to the drawings wherein.

FIG. 1 is a left, perspective view including an endoscopic bipolarforceps showing a housing, a shaft and an end effector assembly havingan insulating boot according to one embodiment of the presentdisclosure;

FIG. 2A is an enlarged, right perspective view of the end effectorassembly with a pair of jaw members of the end effector assembly shownin open configuration having the insulating boot according to thepresent disclosure;

FIG. 2B is an enlarged, bottom perspective view of the end effectorassembly with the jaw members shown in open configuration having theinsulating boot according to the present disclosure;

FIG. 3 is a right, perspective view of another version of the presentdisclosure that includes an open bipolar forceps showing a housing, apair of shaft members and an end effector assembly having an insulatingboot according to the present disclosure;

FIG. 4A is an rear perspective view of the end effector assembly of FIG.1 showing a pair of opposing jaw members in an open configuration;

FIG. 4B is an rear perspective view of the end effector assembly of FIG.1 showing a pair of opposing jaw members in a closed configuration;

FIG. 4C is an side view of the end effector assembly of FIG. 1 showingthe jaw members in a open configuration;

FIG. 5 is an enlarged, schematic side view of the end effector assemblyshowing one embodiment of the insulating boot configured as a mesh-likematerial;

FIG. 6A is an enlarged, schematic side view of the end effector assemblyshowing another embodiment of the insulating boot which includes anenforcement wire disposed longitudinally therealong which is dimensionedto strengthen the boot;

FIG. 6B is a front cross section along line 6B-6B of FIG. 6A;

FIG. 7 is an enlarged, schematic side view of the end effector assemblyshowing another embodiment of the insulating boot which includes wirereinforcing rings disposed at the distal end proximal ends thereof;

FIG. 8A is an enlarged view of a another embodiment of the insulatingboot according to the present disclosure;

FIG. 8B is a front cross section along line 8B-8B of FIG. 8A FIG. 8C isan enlarged view of the insulating boot of FIG. 8A shown in a partiallycompressed orientation;

FIG. 8D is an enlarged side view of the end effector assembly shown withthe insulating boot of FIG. 8A disposed thereon;

FIG. 8E is an enlarged side view of the end effector assembly shown withthe insulating boot of FIG. 8A disposed thereon shown in a partiallycompressed orientation;

FIG. 9A is an enlarged view of another embodiment of the insulating bootaccording to the present disclosure including a mesh and siliconecombination;

FIG. 9B is a greatly-enlarged, broken view showing the radial expansionof the mesh portion of the insulating boot of FIG. 9A whenlongitudinally compressed;

FIG. 10 is an enlarged view of another embodiment of the insulating bootaccording to the present disclosure including a detent and dollop ofadhesive to provide mechanical retention of the insulating boot atop theforceps jaws;

FIG. 11 is an enlarged view of another embodiment of the insulating bootaccording to the present disclosure including a chamfer section whichprovides an inflow channel for the adhesive during curing;

FIG. 12 is an enlarged view of another embodiment of the insulating bootaccording to the present disclosure including an adhesive layer whichseals the junction between the insulating boot and the jaw overmold;

FIG. 13 is an enlarged view of another embodiment of the insulating bootaccording to the present disclosure including a heat activated adhesiveflow ring which facilitates adherence of the insulating boot to the jawmembers;

FIG. 14 is an enlarged view of another embodiment of the insulating bootaccording to the present disclosure which includes a tape layer to holdthe boot against the back of the jaw members;

FIG. 15A is an enlarged view of another embodiment of the insulatingboot according to the present disclosure including a ring of elastomerconnections which both transfer current and facilitate retention of theinsulating boot atop the jaw members;

FIG. 15B is a front cross section along line 15B-15B of FIG. 15A;

FIG. 16 is an enlarged view of another embodiment of the presentdisclosure which includes an insulating sheath filled with silicone gelto facilitate insertion of the cannula within a body cavity;

FIG. 17A is an enlarged view of another embodiment of the presentdisclosure which includes a plastic shield overmolded atop the jawmembers to insulate the jaw members from one another;

FIG. 17B is an enlarged view of a the two jaw members of FIG. 17A shownassembled;

FIG. 18A is an enlarged view of another embodiment of the presentdisclosure similar to FIGS. 17A and 17B wherein a weather stripping isutilized to seal the gap between jaw members when assembled;

FIG. 18B is a front cross section along line 18B-18B of FIG. 18A;

FIG. 19A is an enlarged view of another embodiment of the presentdisclosure which includes an insulating boot with a series of radiallyextending ribs disposed therearound to reduce surface friction of theinsulating boot during insertion through a cannula;

FIG. 19B is a front cross section along line 19B-19B of FIG. 19A;

FIG. 20 is an enlarged view of another embodiment of the presentdisclosure wherein a soft, putty-like material acts as the insulator forthe various moving parts of the jaw members;

FIG. 21 is an enlarged view of another embodiment of the presentdisclosure which includes an insulating shield disposed between the bootand the metal sections of the jaw members;

FIG. 22A is an enlarged view of another embodiment of the presentdisclosure which includes a plastic wedge disposed between the boot andthe proximal end of the jaw members which allows the jaw members topivot;

FIG. 22B is a cross section along line 22B-22B of FIG. 22A;

FIG. 23A is an enlarged view of another embodiment of the presentdisclosure which includes a silicone boot with a ring disposed thereinwhich is composed of an adhesive material which actively fills any holescreated by arcing high current discharges;

FIG. 23B is a cross section along line 23B-23B of FIG. 23A;

FIG. 24A is an enlarged view of another embodiment of the presentdisclosure which includes a silicone boot with an ring disposed thereinwhich is composed of an insulative material which actively fills anyholes created by arcing high current discharges;

FIG. 24B is a cross section along line 24B-24B of FIG. 24A;

FIG. 25 is an enlarged view of another embodiment of the presentdisclosure wherein a distal end of a shaft which is overmolded with asilicone material;

FIG. 26A is an enlarged view of another embodiment of the presentdisclosure which includes an insulating boot being made from a lowdurometer material and a high durometer material—the low durometermaterial being disposed about the moving parts of the jaw members;

FIG. 26B is a cross section along line 26B-26B of FIG. 26A;

FIG. 27 is an enlarged view of another embodiment of the presentdisclosure which includes an insulating ring being made from a highdurometer material;

FIG. 28 is an enlarged view of another embodiment of the presentdisclosure which includes an insulating boot which is packaged with acannula and designed for engagement over the jaw members when the jawmembers are inserted into the cannula;

FIGS. 29A and 29B are enlarged views of other embodiments of the presentdisclosure which include an insulating boot having a tapered distal end;

FIG. 29C is an enlarged view of another embodiment of the presentdisclosure which includes an insulating boot having a square-like taperat the distal end;

FIG. 29D is an enlarged view of another embodiment of the presentdisclosure which includes an insulating boot having a square, taperedsection;

FIG. 30 is an enlarged view of another embodiment of the presentdisclosure which includes an insulating boot having a detent in the jawovermold which is designed to mechanically engage the insulating boot;

FIG. 31 is an enlarged view of another embodiment of the presentdisclosure which includes an insulating boot and a ring-like sleeve;

FIG. 32 is an enlarged view of another embodiment of the presentdisclosure which includes an insulating boot which includes a weatherstrip type mechanical interface disposed at the junction of the boot andthe jaw members;

FIGS. 33A and 33B are enlarged views of another embodiment of thepresent disclosure which includes a co-molded boot having a siliconeportion and proximal and side portions made of a thermoplastic material;

FIG. 34 is an enlarged view of another embodiment having a silicone bootwith a plastic shell overlapped with a heat shrink tubing;

FIGS. 35A-35B is an enlarged view of another embodiment of the presentdisclosure including a thermoplastic clevis having a pair of fingers andwhich project inwardly to mechanically engage the proximal end of jawmembers;

FIG. 36 is an enlarged view of another embodiment of the presentdisclosure which includes a silicone overmolded clevis similar to theembodiment of FIG. 38 which also includes a thermoplastic tubeconfigured to encompass an endoscopic shaft member;

FIG. 37 is an enlarged view of another embodiment of the presentdisclosure with thermoplastic rails along a length thereof;

FIGS. 38A-38D are enlarged views of another embodiment of the presentdisclosure which includes an insulating boot with a ring-like mechanicalinterface which is configured to include a key-like interface forengaging the proximal ends of the jaw members;

FIGS. 39A-39D are enlarged views of another embodiment of the presentdisclosure which includes an insulating boot having a key-like interfacedisposed at a distal end thereof for engaging the proximal ends of thejaw members, the insulating boot being made from a low durometermaterial and a high durometer material;

FIG. 40 are enlarged views of another embodiment of the presentdisclosure which includes a plastic guard rail which secures theinsulating boot to the jaw members and heat shrink material by a seriesof hook-like appendages;

FIG. 41 is an enlarged view of another embodiment of the presentdisclosure which includes an insulating boot having a series of poresdefined in an outer periphery thereof, the pores having a heat activatedlubricant disposed therein to facilitate insertion of the forceps withina cannula;

FIG. 42 is an enlarged view of another embodiment of the presentdisclosure which includes a heat-cured adhesive which is configured tomechanically engage and secure the insulating boot to the jaw members;

FIG. 43 is an enlarged view of another embodiment of the presentdisclosure which includes an insulating boot having an overlappingportion which engages and overlaps the jaw members, the jaw membersincluding a hole defined therein which contains a glue which bonds tothe overlapping portion of the insulating boot;

FIGS. 44A-44B are enlarged views of another embodiment of the presentdisclosure which includes an uncured adhesive sleeve which is configuredto engage the distal end of the shaft and the jaw members and bond tothe uninsulated parts when heated;

FIGS. 45A-45B are enlarged views of another embodiment of the presentdisclosure which includes an insulating boot having an uncured adhesivering which is configured to bond and secure the insulating boot to thejaw members when heated; and

FIG. 46 is an enlarged view of another embodiment of the presentdisclosure which includes a coating disposed on the exposed portions ofthe jaw members, the coating being made from a material that increasesresistance with heat or current.

DETAILED DESCRIPTION

Referring initially to FIGS. 1-2B, one particularly useful endoscopicforceps 10 is shown for use with various surgical procedures andgenerally includes a housing 20, a handle assembly 30, a rotatingassembly 80, a trigger assembly 70 and an end effector assembly 100 thatmutually cooperate to grasp, seal and divide tubular vessels andvascular tissue. For the purposes herein, forceps 10 will be describedgenerally. However, the various particular aspects of this particularforceps are detailed in commonly owned U.S. patent application Ser. No.10/460,926, now U.S. Pat. No. 7,156,846 B2, “VESSEL SEALER AND DIVIDERFOR USE WITH SMALL TROCARS AND CANNULAS”, issued to Dycus et al. on Jan.2, 2007, U.S. patent application Ser. No. 10/953,757, now U.S. Pat. No.7,150,749 B2, “VESSEL SEALER AND DIVIDER HAVING ELONGATED KNIFE STROKEAND SAFETY CUTTING MECHANISM”, issued to Dycus et al. on Dec. 19, 2006,and U.S. patent application Ser. No. 11/348,072, now U.S. Pat. No.7,771,425 B2, “VESSEL SEALER AND DIVIDER HAVING A VARIABLE JAW CLAMPINGMECHANISM”, issued to Dycus et al. on Aug. 10, 2010.

Forceps 10 also includes a shaft 12 that has a distal end 16 dimensionedto mechanically engage the end effector assembly 100 and a proximal end14 that mechanically engages the housing 20 through rotating assembly80. As will be discussed in more detail below, the end effector assembly100 includes a flexible insulating boot 500 configured to cover at leasta portion of the exterior surfaces of the end effector assembly 100.

Forceps 10 also includes an electrosurgical cable 310 that connects theforceps 10 to a source of electrosurgical energy, e.g., a generator (notshown). The generator includes various safety and performance featuresincluding isolated output, independent activation of accessories, andInstant Response™ technology (a proprietary technology of Valleylab,Inc., a division of Tyco Healthcare, LP) that provides an advancedfeedback system to sense changes in tissue many times per second andadjust voltage and current to maintain appropriate power. Cable 310 isinternally divided into a series of cable leads (not shown) that eachtransmit electrosurgical energy through their respective feed pathsthrough the forceps 10 to the end effector assembly 100.

Handle assembly 30 includes a two opposing handles 30 a and 30 b whichare each movable relative to housing 20 from a first spaced apartposition wherein the end effector is disposed in an open position to asecond position closer to housing 20 wherein the end effector assembly100 is positioned to engage tissue. Rotating assembly 80 is operativelyassociated with the housing 20 and is rotatable in either directionabout a longitudinal axis “A” (See FIG. 1). Details of the handleassembly 30 and rotating assembly 80 are described in theabove-referenced patent applications, namely, U.S. patent applicationSer. No. 10/460,926, now U.S. Pat. No. 7,156,846 B2, U.S. patentapplication Ser. No. 10/953,757, now U.S. Pat. No. 7,150,749 B2, andU.S. patent application Ser. No. 11/348,072, now U.S. Pat. No. 7,771,425B2.

As mentioned above and as shown best in FIGS. 2A and 2B, end effectorassembly 100 is attached at the distal end 14 of shaft 12 and includes apair of opposing jaw members 110 and 120. Opposing handles 30 a and 30 bof handle assembly 30 are ultimately connected to a drive assembly (notshown) that, together, mechanically cooperate to impart movement of thejaw members 110 and 120 from an open position wherein the jaw members110 and 120 are disposed in spaced relation relative to one another, toa clamping or closed position wherein the jaw members 110 and 120cooperate to grasp tissue therebetween. All of these components andfeatures are best explained in detail in the above-identified commonlyowned U.S. application Ser. No. 10/460,926, now U.S. Pat. No. 7,156,846B2.

FIG. 3 shows insulating boot 500 configured to engage a forceps 400 usedin open surgical procedures. Forceps 400 includes elongated shaftportions 412 a and 412 b having an end effector assembly 405 attached tothe distal ends a and 416 b of shafts 412 a and 412 b, respectively. Theend effector assembly 405 includes pair of opposing jaw members 410 and420 which are pivotably connected about a pivot pin 465 and which aremovable relative to one another to grasp tissue.

Each shaft 412 a and 412 b includes a handle 415 a and 415 b,respectively, disposed at the proximal ends thereof. As can beappreciated, handles 415 a and 415 b facilitate movement of the shafts412 a and 412 b relative to one another which, in turn, pivot the jawmembers 410 and 420 from an open position wherein the jaw members 410and 420 are disposed in spaced relation relative to one another to aclamping or closed position wherein the jaw members 410 and 420cooperate to grasp tissue therebetween. Details relating to the internalmechanical and electromechanical components of forceps 400 are disclosedin commonly-owned U.S. patent application Ser. No. 10/962,116, now U.S.Pat. No. 7,811,283 B2, “OPEN VESSEL SEALING INSTRUMENT WITH HOURGLASSCUTTING MECHANISM AND OVER-RATCHET SAFETY”, issued to Moses et al. onOct. 12, 2010. As will be discussed in more detail below, an insulatingboot 500 or other type of insulating device as described herein may beconfigured to cover at least a portion of the exterior surfaces of theend effector assembly 405 to reduce stray current concentrations duringelectrical activation.

As best illustrated in FIG. 3, one of the shafts, e.g., 412 b, includesa proximal shaft connector 470 which is designed to connect the forceps400 to a source of electrosurgical energy such as an electrosurgicalgenerator (not shown). The proximal shaft connector 470electromechanically engages an electrosurgical cable 475 such that theuser may selectively apply electrosurgical energy as needed. The cable470 connects to a handswitch 450 to permit the user to selectively applyelectrosurgical energy as needed to seal tissue grasped between jawmembers 410 and 420. Positioning the switch 450 on the forceps 400 givesthe user more visual and tactile control over the application ofelectrosurgical energy. These aspects are explained below with respectto the discussion of the handswitch 450 and the electrical connectionsassociated therewith in the above-mentioned commonly-owned U.S. patentapplication Ser. No. 10/962,116, now U.S. Pat. No. 7,811,283 B2.

A ratchet 430 is included which is configured to selectively lock thejaw members 410 and 420 relative to one another in at least one positionduring pivoting. A first ratchet interface 431 a extends from theproximal end of shaft member 412 a towards a second ratchet interface431 b on the proximal end of shaft 412 b in general verticalregistration therewith such that the inner facing surfaces of eachratchet 431 a and 431 b abut one another upon closure of the jaw members410 and 420 about the tissue. The ratchet position associated with thecooperating ratchet interfaces 431 a and 431 b holds a specific, i.e.,constant, strain energy in the shaft members 412 a and 412 b which, inturn, transmits a specific closing force to the jaw members 410 and 420.

The jaw members 410 and 420 are electrically isolated from one anothersuch that electrosurgical energy can be effectively transferred throughthe tissue to form a tissue seal. Jaw members 410 and 420 both include auniquely-designed electrosurgical cable path disposed therethrough whichtransmits electrosurgical energy to electrically conductive sealingsurfaces 412 and 422, respectively, disposed on the inner facingsurfaces of jaw members, 410 and 420.

Turning now to the remaining figures, FIGS. 4A-46, various envisionedembodiments of electrical insulating devices are shown for shielding,protecting or otherwise limiting or directing electrical currents duringactivation of the forceps 10, 400. More particularly, FIGS. 4A-4C showone embodiment wherein the proximal portions of the jaw members 110 and120 and the distal end of shaft 12 are covered by the resilientinsulating boot 500 to reduce stray current concentrations duringelectrosurgical activation especially in the monopolar activation mode.More particularly, the boot 500 is flexible from a first configuration(See FIG. 4B) when the jaw members 110 and 120 are disposed in a closedorientation to a second expanded configuration (See FIGS. 4B and 4C)when the jaw members 110 and 120 are opened. When the jaw members 110and 120 open, the boot flexes or expands at areas 220 a and 220 b toaccommodate the movement of a pair of proximal flanges 113 and 123 ofjaw members 110 and 120, respectively (see FIGS. 17A and 17B). Furtherdetails relating to one envisioned insulating boot 500 are describedwith respect to commonly-owned U.S. application Ser. No. 11/529,798entitled “INSULATING BOOT FOR ELECTROSURGICAL FORCEPS”,”, now U.S. Pat.No. 7,846,161 B2 issued to Dumbauld et al. on Dec. 7, 2010, the entirecontents of which being incorporated by reference herein.

FIG. 5 shows another embodiment of an insulating boot 600 which isconfigured to reduce stray current concentrations during electricalactivation of the forceps 10. More particularly, the insulating boot 600includes a woven mesh 620 which is positioned over a proximal end of thejaw members 110 and 120 and a distal end of the shaft 12. Duringmanufacturing, the mesh 620 is coated with a flexible silicone-likematerial 610 which is designed to limit stray currents from emanating tosurrounding tissue areas. The woven mesh 620 is configured to providestrength and form to the insulating boot 600. The woven mesh 620 is alsoconfigured to radially expand when the mesh 620 longitudinally contracts(See FIGS. 9A and 9B).

FIGS. 6A and 6B show another embodiment of an insulating boot 700 whichincludes a pair of longitudinally extending wires 720 a and 720 bencased within corresponding channels 710 a and 710 b, respectively,defined within the boot 700. The wires 720 a and 720 b re-enforce theboot 700 and may be manufactured from conductive or non-conductivematerials. As can be appreciated, any number of wires 720 a and 720 bmay be utilized to support the insulating boot 700 and enhance the fitof the boot 700 atop the jaw members 110 and 120. The wires 720 a and720 b may be adhered to an outer periphery of the boot 700, adhered toan inner periphery of the boot 700, recessed within one or more channelsdisposed in the outer or inner periphery of the boot 700 or co-extrudedor insert-molded into the insulating boot 700. The wires 720 a and 720 bmay be manufactured from a flexible metal, surgical stainless steel,NiTi, thermoplastic, polymer, high durometer material and combinationsthereof.

FIG. 7 shows another embodiment of an insulating boot 800 which includesa pair of circumferential wires 820 a and 820 b disposed within or atopthe boot 800. The wires 820 a and 820 b re-enforce the boot 700 at theproximal and distal ends thereof and may be manufactured from conductiveor non-conductive materials such as flexible metals, surgical stainlesssteel, NiTi, thermoplastic and polymers. Due to the tensile strength ofthe wires 820 a and 820 b, the boot 800 stays in place upon insertionthough a cannula and further prevents the boot 800 from rolling ontoitself during repeated insertion and/or withdrawal from a cannula. Ascan be appreciated, any number of wires 820 a and 820 b may be utilizedto support the insulating boot 800 and enhance the fit of the boot atopthe jaw members 110 and 120. For example, in one embodiment, the wiresare insert molded to the boot 800 during a manufacturing step.

FIGS. 8A-8E show yet another embodiment of an insulating boot 900 whichincludes a molded thermoplastic shell 905 having a series of slits 930a-930 d disposed therethrough which are configured to flex generallyoutwardly (See FIGS. 8C and 8E) upon the travel of the forceps shaft 12to actuate the jaw members 110 and 120 to the open configuration. Shell905 includes an inner periphery thereof lined with a silicone-likematerial 910 a and 910 b which provides patient protection fromelectrosurgical currents during activation while outer thermoplasticshell 905 protects the silicone material 910 a and 910 b duringinsertion and retraction from a surgical cannula (not shown). The outershell 905 and the silicone-like material 910 a and 910 b may beovermolded or co-extruded during assembly.

As mentioned above, the outer shell 905 expands at expansion points 935a and 935 b upon contraction of the shaft 12 or movement of the jawmembers 110 and 120. During expansion of the shell 905, the shell 905does not adhere to the inner silicone material 910 a and 910 b due theinherent properties of the silicone material 910 a and 910 b andselective texturing thereof. Shell 905 may also include an inner rim orlatching areas 915 a and 915 b disposed at the distal (and/or proximal)end thereof. The latching areas 915 a and 915 b are configured tomechanically interface with the jaw members 110 and 120 and hold theshell 905 in place during relative movement of the shaft 12. Othermechanical interfaces 908 may also be included which are configured toengage the shell 905 with the jaw members and/or shaft 12, e.g.,adhesive. The outer shell 905 may include a relief section 911 tofacilitate engagement of the outer shell 905 atop the jaw members 110and 120.

FIGS. 9A and 9B show yet another embodiment of the insulating boot 1000which is configured to include an insulative mesh 1010 disposed at oneend of boot 1000 and a silicone (or the like) portion 1020 disposed atthe other end thereof. Mesh portion 1010 is configured to radiallyexpand and longitudinally contract from a first configuration 1010 to asecond configuration 1010′ as shown in FIG. 9B. The mesh portion 1010 istypically associated with the part of the boot closest to the jawmembers 110 and 120.

FIG. 10 shows yet another embodiment of the insulating boot 1100 whichis configured to mechanically engage a corresponding mechanicalinterface 1110 (e.g., detent or bump) disposed on a proximal end of thejaw members, e.g., jaw member 110. An adhesive 1120 may also be utilizedto further mechanical retention. The at least one mechanical interface1110 may also include a raised protuberance, flange, spike, cuff, rim,bevel and combinations thereof. The mechanical interface 1110 may beformed by any one of several known processes such as co-extrusion andovermolding.

Similarly, one or both jaw members 110 and 120 may include anunderlapped or chamfered section 1215 which enhances mechanicalengagement with the insulating boot 1200. For example and as best shownin FIG. 11, an adhesive 1210 may be utilized between the beveled section1215 defined in jaw member 110 and the insulating boot 1200 to enhancemechanical engagement of the boot 1200. Further and as best shown inFIG. 12, an adhesive 1410 may be disposed atop the intersection orabutment of the bevel 1415 and insulating boot 1400 to furthermechanical retention of the boot 1400. The adhesive 1410 may beconfigured to cure upon application of heat, ultraviolet light,electrical energy or other ways customary in the trade.

FIG. 13 shows yet another embodiment of an insulating boot 1300 whichincludes an internally-disposed glue ring 1310 disposed along the innerperiphery 1320 of the boot 1300. The glue ring 1310 is configured tocure when heated or treated with light (or other energy) depending upona particular purpose or manufacturing sequence.

FIG. 14 shows yet another embodiment of an insulating boot 1500 which isconfigured to cooperate with a glue-like tape 1510 which holds thedistal end 1515 of the insulating boot 1500 in place atop the proximalends 111 and 121 of the jaw members 110 and 120, respectively. Tape 1510may be configured to cure upon application of heat or other energy. Thetape 1510 may also be configured to include an aperture 1511 definedtherein which is dimensioned to receive the proximal end of the jawmembers 110 and 120.

FIGS. 15A and 15B show yet another embodiment of an insulating boot 1600which includes a series of electrical leads 1610 a-1610 h disposedtherethrough which are designed to electromechanically engage the jawmembers 110 and 120 and supply current thereto. More particularly, boot1600 may include leads 1610 a-1610 d which carry on electrical potentialto jaw member 110 and leads 1610 e-1610 h which are designed to carry asecond electrical potential to jaw member 120. The leads 1610 a-1610 hmay be configured as metal strands disposed along the inner peripheralsurface of boot 1600 which are configured to provide electricalcontinuity to the jaw members 110 and 120. The leads 1610 a-1610 f maybe co-extruded or insert molded to the inner periphery of the boot 1600.At least one of the leads 1610 a-1610 h may be configured to carry ortransmit a first electrical potential and at least one of the leads 1610a-1610 h may be configured to carry a second electrical potential.

FIG. 16 shows yet another version of an insulating sheath or boot 1700which is configured to be removable prior to insertion through a cannula(not shown). Boot 1700 is designed like a condom and is filled with asilicone lube 1710 and placed over the distal end of jaw members 110 and120. Prior to insertion of the forceps 10 through a cannula, the boot1700 is removed leaving residual silicone 1710 to facilitate insertionthrough the cannula. The forceps 10 may also include a second insulatingboot 500 to reduce current concentrations similar to any one of theaforementioned embodiments or other embodiments described herein.

The present disclosure also relates to a method of facilitatinginsertion of a forceps through a cannula and includes the steps ofproviding a forceps including a shaft having a pair of jaw members at adistal end thereof. The jaw members are movable about a pivot from afirst position wherein the jaw members are disposed in spaced relationrelative to one another to a second position wherein the jaw members arecloser to one another for grasping tissue. At least one of the jawmembers is adapted to connect to a source of electrical energy such thatthe at least one jaw member is capable of conducting energy to tissueheld therebetween. An insulative sheath is disposed atop at least aportion of an exterior surface of at least one jaw member, about thepivot and the distal end of the shaft. The insulative sheath houses asilicone lube configured to facilitate insertion of the forceps througha cannula after removal of the insulative sheath.

The method also includes the steps of removing the insulative sheath toexpose the silicone lube atop the exterior surface of at least one jawmember, about the pivot and the distal end of the shaft, engaging theforceps for insertion through a cannula and inserting the forcepsthrough the cannula utilizing the silicone lube to facilitate insertion.

FIGS. 17A and 17B show still another embodiment of the insulating boot1800 which is configured as elastomeric shields 1800 a and 1800 b whichare overmolded atop the proximal ends of respective jaw members 110 and120 during a manufacturing step. A retention element (e.g., mechanicalinterface 1110) may also be included which engages one or both shields1800 a, 1800 b. Once the forceps 10 is assembled, the elastomericshields 1800 a and 1800 b are configured to abut one another to reducestray current concentrations. FIGS. 18A and 18B show a similar versionof an insulating boot 1900 which includes two overmolded elastomericshields 1900 a and 1900 b which are mechanically engaged to one anotherby virtue of one or more weather strips 1910 a and 1910 b. Moreparticularly, the weather strips 1910 a and 1910 b are configured toengage and seal the two opposing shields 1900 a and 1900 b on respectivejaw members 110 and 120 during the range of motion of the two jawmembers 110 and 120 relative to one another.

FIGS. 19A and 19B show yet another embodiment of the insulating boot2000 which includes an elastomeric or silicone boot similar to boot 500wherein the outer periphery of the boot 2000 includes a plurality ofribs 2010 a-2010 h which extend along the length thereof. It iscontemplated that the ribs 2010 a-2010 h reduce the contact area of theboot 2000 with the inner periphery of a cannula (not shown) to reducethe overall surface friction of the boot during insertion into andwithdrawal from the cannula.

FIG. 20 shows still another embodiment of the insulating boot 2100 whichincludes a soft caulk or putty-like material 2110 formed atop or withinthe boot which is configured to encapsulate the moving parts of theforceps 10. As best shown in FIG. 21, an overmolded section 114′ may beformed over the proximal flange 113 of the jaw members, e.g., jaw member110, to provide a rest for the insulating boot 500 (or any other versiondescribed above).

FIGS. 22A and 22B show yet another embodiment of an insulating boot 2200which includes a plastic wedge-like material 2210 formed between theboot 2200 and the proximal ends 110′ and 120′ of the jaw members, e.g.,jaw member 110 and jaw member 120, respectively. As best illustrated inthe cross-section view of FIG. 22B, the plastic wedge-like materialforms an upper wedge 2210 a and a lower wedge 2210 b that are configuredto allow a range of motion of the jaw members 110 and 120 while keepingthe boot 2200 intact atop the shaft 12 and the moving flanges 113 and123 of the jaw members 110 and 120, respectively.

FIGS. 23A and 23B show still another envisioned embodiment of aninsulating boot 2300 which includes an outer silicone-like shell 2310which is dimensioned to house a layer of high resistance adhesivematerial 2320. If high current flowing through the insulating boot 2300causes a rupture in the boot 2300, the adhesive material 2320 melts andflows through the ruptured portion to reduce the chances of currentleakage during activation. FIGS. 24A and 24B show a similar insulativeboot 2400 wherein the insulative boot 2400 includes a free flowingmaterial which is designed to flow through the ruptured portion toprovide additional insulation from current during activation. Moreparticularly, the boot 2400 includes an internal cavity 2410 definedtherein which retains a free-flowing material 2420. The free-flowingmaterial 2420 is configured to disperse from the internal cavity 2410when ruptured. The free-flowing material 2420 may be a high resistiveadhesive, a lubricating material or an insulating material orcombinations thereof. The internal cavity 2410 may be annular anddisposed on a portion or the boot 2400 or may be longitudinal anddisposed along a portion of the boot 2400. The free-flowing material2420 may be configured to change state between a solid state and aliquid state upon the application of energy (e.g., heat energy) or light(e.g., ultraviolet). The free-flowing material 2420 may be disposed oneither the distal and/or proximal ends of the flexible insulating boot2400.

FIG. 25 shows yet another embodiment of the insulating boot 2500 whereinthe distal end of the shaft 12 and the jaw members 110 and 120 areovermolded during manufacturing with a silicone material (or the like)to protect against stray current leakage during activation.

FIGS. 26A, 26B and 27 show other embodiments of insulating boots 2600and 2700, respectively, wherein boots 2600 and 2700 include lowdurometer portions and high durometer portions. The boots 2600 and 2700may be formed from a two-shot manufacturing process. More particularly,FIGS. 26A and 26B include a boot 2600 with a high durometer portion 2610having an elongated slot of low durometer material 2620 disposed thereinor therealong. The low durometer portion 2620 is dimensioned toencapsulate the moving flanges 113 and 123 of the jaw members 110 and120, respectively. FIG. 27 shows another embodiment wherein a ring ofhigh durometer material 2710 is disposed at the distal end of the boot2700 for radial retention of the jaw members 110 and 120. The remainderof the boot 2700 consists of low durometer material 2720.

FIG. 28 shows another embodiment of the present disclosure wherein theinsulating boot 2800 may be packaged separately from the forceps 10 anddesigned to engage the end of the shaft 12 and jaw members 110 and 120upon insertion though a cannula 2850. More particularly, boot 2800 maybe packaged with the forceps 10 (or sold with the cannula 2850) anddesigned to insure 90 degree insertion of the forceps 10 through thecannula 2850. The boot 2800 in this instance may be made from silicone,plastic or other insulating material.

FIGS. 29A-29D include various embodiments of a boot 2900 having atapered distal end 2920 and a straight proximal end 2910. Moreparticularly, FIG. 29A shows a tapered bottle-like distal end 2920 whichis configured to provide enhanced retentive force at the distal end ofthe forceps 10 which reduces the chances of the boot 2900 slipping fromthe boot's 2900 intended position. FIG. 29B shows another version of thetapered boot 2900′ which includes a sharply tapered distal end 2920′ anda straight proximal end 2910′. FIG. 29C shows another boot 2900″ whichincludes a square-like taper 2920″ at the distal end thereof and astraight proximal end 2910″. FIG. 29D shows yet another version of atapered boot 2900′″ which includes a square, tapered section 2930′″disposed between distal and proximal ends, 2920′″ and 2910′″,respectively. The outer diameter of the insulating boot 2900 or theinner periphery of the insulating boot 2900 may include the taperedsection.

FIG. 30 shows yet another embodiment of the presently disclosed boot3000 which is configured to be utilized with a jaw member 110 having aproximal overmolded section 114′ similar to the jaw members disclosedwith respect to FIG. 21 above. More particularly, jaw member 110includes proximal overmolded section 114′ having a bump or protrusion115′ disposed thereon. Bump 115′ is configured to mechanically cooperatewith a corresponding portion 3010 of boot 3000 to enhance retention ofthe boot 3000 atop the jaw member 110.

FIG. 31 shows still another embodiment of an insulating boot 500 whichincludes a silicone (or similar) ring-like sleeve 3100 which isconfigured to engage and secure the boot 500 atop the shaft 12. FIG. 32shows a similar boot 500 configuration wherein a pair of weather strips3200 a and 3200 b are positioned to secure the boot 500 at the junctionpoint between the end of shaft 12 and the proximal end of the jawmembers 110 and 120.

FIGS. 33A-33B show yet another embodiment of a co-molded boot 3300having a silicone portion 3305 and proximal and side portions 3310 c,3310 a and 3310 b made of a thermoplastic material (or the like). Thethermoplastic materials 3310 a-3310 c enhance the rigidity anddurability of the boot 3300 when engaged atop the jaw members 110 and120 and the shaft 12. Thermoplastic portions 3310 a and 3310 b may bedimensioned to receive and/or mate with the proximal flanges 113 and 123of jaw members 110 and 120, respectively.

FIG. 34 shows yet another embodiment of an insulating boot having asilicone boot 3350 mounted under a plastic shell 3355. A heat shrinktubing (or the like) 3360 is included which overlaps at least a portionof the plastic shell 3355 and silicone boot 3350.

FIGS. 35A and 35B show still another embodiment of an insulating boot3400 which includes an overmolded thermoplastic clevis 3410 disposed onan inner periphery thereof which is configured to enhance the mechanicalengagement of the boot 3400 with the jaw members 110 and 120 and shaft12. More particularly, the clevis 3410 includes a pair of fingers 3410 aand 3410 b which project inwardly to mechanically engage the proximalend of jaw members 110 and 120. The proximal end of the boot 3400 fitsatop the end of shaft 12 much like the embodiments described above (SeeFIG. 35B). An outer shell 3402 is disposed atop the overmoldedthermoplastic clevis 3410 to enhance the rigidity of the boot 3400. Theclevis 3410 includes a channel 3412 defined between the two fingers 3410a and 3410 b which facilitates movement of the jaw members 110 and 120.

FIG. 36 shows yet another embodiment of an insulating boot 3500 which issimilar to boot 3400 described above with respect to FIGS. 35A and 35Band includes a thermoplastic clevis 3510 having a pair of fingers 3510 aand 3510 b which project inwardly to mechanically engage the proximalend of jaw members 110 and 120. Boot 3500 also includes outerthermoplastic portions 3520 a and 3520 b which are configured to furtherenhance the rigidity of the boot 3500 and act as a so-called“exoskeleton”. A channel 3515 is defined between in the outerexoskeleton to facilitate movement of the jaw members 110 and 120. Thetwo outer portions 3520 a and 3520 b also include a relief portion 3525disposed therebetween which allows the boot 3500 to expand during therange of motion of jaw members 110 and 120.

FIG. 37 shows yet another embodiment of an insulating boot 3600 whichincludes a plurality of thermoplastic rails 3610 a-3610 d disposed alongthe outer periphery thereof. The rails 3610 a-3610 d may be formedduring the manufacturing process by overmolding or co-extrusion and areconfigured to enhance the rigidity of the boot 3600 similar to theembodiment described above with respect to FIG. 19B.

FIGS. 38A-38D show still another embodiment of an insulating boot 3700which includes a low durometer portion 3725 generally disposed at theproximal end 3720 thereof and a high durometer portion 3730 generallydisposed at the distal end 3710 thereof. The high durometer portion 3730may be configured to mechanically engage the low durometer portion 3725or may be integrally associated therewith in a co-molding orover-molding process. The inner periphery 3750 of the high durometerportion 3730 is dimensioned to receive the flanges 113 and 123 of jawmembers 110 and 120, respectively. The low durometer portion 3725 may bedimensioned to allow the proximal ends 113 and 123 of flanges to flexbeyond the outer periphery of the shaft 12 during opening of the jawmembers 110 and 120. It is also contemplated that the high durometerportion 3730 (or a combination of the high durometer portion 3730 andthe low durometer portion 3725) may act to bias the jaw members 110 and120 in a closed orientation.

FIGS. 39A-39D show yet another embodiment of an insulating boot 3800which includes a low durometer portion 3825 and a high durometer portion3830 generally disposed at the distal end 3810 thereof. The highdurometer portion 3830 includes proximally-extending fingers 3820 a and3820 b which define upper and lower slots 3840 a and 3840 b,respectively, dimensioned to receive upper and lower low durometerportions 3825 a and 3825 b, respectively. The inner periphery 3850 ofthe high durometer portion 3830 is dimensioned to receive flanges 113and 123 of jaw members 110 and 120, respectively. It is alsocontemplated that the high durometer portion 3830 (or a combination ofthe high durometer portion 3830 and the low durometer portions 3825 aand 3825 b) may act to bias the jaw members 110 and 120 in a closedorientation.

FIG. 40 shows yet another version of an insulating boot 3900 whichincludes a pair of hook-like mechanical interfaces 3900 a and 3900 bwhich are designed to engage the jaw members 110 and 120 at one end(e.g., the hook ends 3905 a and 3905 b) and designed to engage the shaft12 at the opposite ends 3908 a and 3908 b, respectively. Moreparticularly, the boot 3900 includes a pair of rails or slots 3912 a and3912 b defined in an outer periphery thereof which are dimensioned toreceive the corresponding hook-like mechanical interfaces 3900 a and3900 b therealong. The proximal ends 3908 a and 3908 b of the hook-likemechanical interfaces 3900 a and 3900 b are configured to secure aboutthe shaft 12 during an initial manufacturing step and then are held inplace via the employment of heat shrink wrapping 12′. The heat shrinkwrapping 12′ prevents the hook-like mechanical interfaces 3900 a and3900 b from slipping during insertion and removal of the forceps 10through a cannula.

FIG. 41 shows still another version of an insulating boot 4000 whichincludes a series of pores 4010 a-4010 f disposed along the outerperiphery thereof. A heat-activated adhesive or lubricant 4030 isincluded in the pores 4010 a-4010 f such that when the lubricant 4030 isheated, the lubricant 4030 flows freely over the boot 4000 therebyfacilitating insertion and withdrawal of the forceps 10 from a cannula.

FIG. 42 shows still another embodiment of an insulating boot 500 whichincludes a strip of heat activated adhesive 4100 to secure the boot 500to the jaw members 110 and 120. The heat activated adhesive 4100 isdesigned to cure upon the application of heat to prevent unwanted motionbetween the two jaw members 110 and 120 or between the jaw members 110and 120 and the shaft 12. FIG. 43 shows a similar concept which includesan insulating boot 4200 having a pair of overlapping flanges 4220 a and4220 b which extend toward the jaw members 110 and 120 and whichcooperate with one or more apertures (not shown) defined in the proximalflanges 113 and 123 of the jaw members 110 and 120 to retain aheat-activated adhesive 4230 therein. Once heated, the adhesive 4230cures and maintains a strong, low profile bond between the boot 4200 andthe jaw members 110 and 120.

FIGS. 44A and 44B show still another embodiment of an insulating boot4300 which involves a two-step process for deployment atop the jawmembers 110 and 120. During an initial manufacturing step the boot 4300is in the form of an uncured adhesive sleeve 4300 and is fitted atop theproximal ends of the jaw members 110 and 120 and the shaft 12. Onceproperly positioned, the uncured adhesive sleeve 4300 is then curedusing heat or UV light such that the cured boot 4300′ creates aconformal coating atop the jaw members 110 and 120 and acts to securethe boot 4300′ to the jaw members 110 and 120 and shaft 12 and insulatethe surrounding tissue from negative electrical and thermal effects.

FIGS. 45A and 45B show still another embodiment of an insulating boot4400 which also involves a two-step process for deployment atop the jawmembers 110 and 120. During an initial manufacturing step the boot 4400includes a ring of uncured adhesive material 4410 disposed along aninner periphery thereof. The boot 4400 with the uncured adhesive ring4410 is fitted atop the proximal ends of the jaw members 110 and 120 andthe shaft 12. Once properly positioned, the uncured adhesive ring 4410is then cured using heat or UV light such that the cured boot 4400′conforms atop the jaw members 110 and 120 and acts to secure the boot4400′ to the jaw members 110 and 120 and shaft 12.

FIG. 46 shows still another embodiment of the present disclosure whichincludes a coating 110′ and 120′ disposed on the exposed portions of thejaw members 110 and 120. The coating 110′ and 120′ may be made from aninsulating material or made from a material that increases resistancewith heat or current. The tip portion 111 of the jaw members 110 isexposed and does not include the coating material such thatelectrosurgical energy may be effectively transferred to tissue via theexposed tip portion 111.

As mentioned above, the insulating boot 500 may be from any type ofvisco-elastic, elastomeric or flexible material that is biocompatibleand that is configured to minimally impede movement of the jaw members110 and 120 from the open to closed positions. The insulating boot 1500may also be made at least partially from a curable material whichfacilitates engagement atop the jaw members 110 and 120 and the shaft12. The presently disclosed insulating boots 500-4400′ described hereinabove may also be utilized with any of the forceps designs mentionedabove for use with both endoscopic surgical procedures and open surgicalprocedures and both bipolar electrosurgical treatment of tissue (eitherby vessel sealing as described above or coagulation or cauterizationwith other similar instruments) and monopolar treatment of tissue.

The aforedescribed insulating boots, e.g., boot 500, unless otherwisenoted, are generally configured to mount over the pivot, connecting jawmember 110 with jaw member 120. The insulating boots, e.g., boot 500, isflexible to permit opening and closing of the jaw members 110 and 120about the pivot.

From the foregoing and with reference to the various figure drawings,those skilled in the art will appreciate that certain modifications canalso be made to the present disclosure without departing from the scopeof the same. For example and although the general operating componentsand inter-cooperating relationships among these components have beengenerally described with respect to a vessel sealing forceps, otherinstruments may also be utilized that may be configured to include anyof the aforedescribed insulating boots to allow a surgeon to safely andselectively treat tissue in both a bipolar and monopolar fashion. Suchinstruments include, for example, bipolar grasping and coagulatinginstruments, cauterizing instruments, bipolar scissors, etc.

Furthermore, those skilled in the art recognize that while theinsulating boots described herein are generally tubular, thecross-section of the boots may assume substantially any shape such as,but not limited to, an oval, a circle, a square, or a rectangle, andalso include irregular shapes necessary to cover at least a portion ofthe jaw members and the associated elements such as the pivot pins andjaw protrusions, etc.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of particular embodiments. Those skilled in the artwill envision other modifications within the scope and spirit of theclaims appended hereto.

The invention claimed is:
 1. An electrosurgical forceps, comprising: ashaft having a pair of jaw members at a distal end thereof, the jawmembers being movable about a pivot from a first position wherein thejaw members are disposed in spaced relation relative to one another to asecond position wherein the jaw members are closer to one another forgrasping tissue, at least one jaw member adapted to connect to a sourceof electrical energy such that the jaw members are capable of conductingenergy to tissue held therebetween; a movable handle that actuates adrive assembly to move the jaw members relative to one another; at leastone of the jaw members including at least one mechanical interface, anda flexible insulating boot disposed on at least a portion of an exteriorsurface of at least one jaw member and about the pivot, the flexibleboot including a first longitudinal portion made from a high durometermaterial and a second longitudinal portion made from a low durometermaterial, the high durometer portion including proximally-extendingfingers which define upper and lower slots therein dimensioned toreceive corresponding upper and lower low durometer portions duringco-extrusion of the flexible insulating boot.
 2. An electrosurgicalforceps according to claim 1 wherein each jaw member includes a proximalflange associated therewith and the shaft defines an outer periphery andwherein the low durometer material is oriented to stretch and allow theproximal flange of each jaw member to rotate beyond the outer peripheryof the shaft.